In a large saucepan, cook onion with a pinch of salt over medium heat until fragrant, about 3-4 minutes. Add cauliflower, 500g cooked turkey meat and turkey stock.
Bring to a boil then lower heat and simmer uncovered until cauliflower is fork tender.
Remove from heat and allow to cool for a few minutes before transferring to your high speed blender or food processor.
Add arrowroot flour and process on high speed then transfer the soup back to the saucepan.
Throw in the remaining 200g of leftover turkey meat, bring back to a simmer and continue cooking for a few minutes until the chunks of meat are nice and warm.
*I made my own turkey stock by throwing the carcass along with everything that was in it (apples, oranges and sage) in enough water to cover all and I let that simmer for about 2 hours. I then strained my stock and put it in the fridge to cool completely, which made removing the very thin layer of fat that solidified on the surface super easy. Mayo Clinic also has an excellent recipe for low fat chicken stock. You can use the same method to make turkey stock.
Cream of Turkey Soup https://thehealthyfoodie.com/healthy-and-comforting-cream-of-turkey-soup/